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- J. JOHNSTON.

SAFETY LATOH FOB. ELEVATOR DOORS. No. 425,802.

INVENTOH A TTOHNEYS Patented Ap TN: nouns Pzfzusca, Puma-mm, wnnmmcx n cW/T/VESSES UNITEDv STATES PATENT OFFICE.

JOHN JOHNSTON," OF NEW YORK, N. Y.

SAFETY- LATCH FOR ELEVATOR-DOORS.

SPECIFICATION forming part of Letters Patent No. 425,802, dated April15, 1890.0

To all whom, it may concern:

Be it known that I, JOHN JOHNSTON, of New York city, in the county andState of New York, have invented a new and Improved Safety-Latch forElevator-Doors, of which the following is a full, clear, and exactdescription.

My invention relates to a safety-latch for elevator-doors, and has forits object to provide a means whereby an elevator-car, in ascending ordescending, upon reaching a floor will automatically unbolt theshaft-door and permit the same to be opened; and also wherein, beforethe elevator-car leaves the floor, if the shaft-door is closed said doorwill be automatically locked.

A further object of the invention is to provide a device of simple anddurable construction capable of accomplishing the above results and ofattachment to any shaft.

The invention consists in the novel construction and combination of theseveral parts, as will be hereinafter fully set forth, and pointed outin the claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar figures of reference indicatecorresponding parts in all the views.

Figure 1 is a vertical section through the elevator-car and a partialvertical section through the shaft, illustrating the said shaft and caras fitted with my improvement; and Fig. 2 is an enlarged section of aportion of the shaft and door and a portion of the car.

The door of the elevator-shaft 11 may be either a sliding or a swingdoor, and is provided at any point between its top and bottom on oneedge, preferably at its center, with a keeper 12. Upon the inner face ofthe doorjamb 13, near the keeper 12 when the door is closed, a strap 14is vertically secured, within which strap the inner end of a latch 15 iscocentrically pivoted. The latch 15 is provided with a suitable headadapted to engage with the keeper 12 of the door, and the inner orpivotal end is somewhat circular in general contour and provided belowthe fulcrum upon its under side with a series of teeth 16. These teethare adapted to mesh with teeth 17, formed in the upper edge of a bar 18,which for convenience I term a rack-bar, the said rack-bar being adaptedto slide in the strap 14, and also in a second strap 19, attached to thejamb at or near its inner edge.

The rack-bar '18 extends beyond the inner strap 19, and a spring bearsat its upper end against the inner extremity of said rackbar,whichspring is secured at its lower end in any suitable or approvedmanner to the inner edge of the jamb 13, the central portion of thespring being bowed or curved to project within the elevator-shaft, thespring employed being usually a strap-spring.

The elevator-car 21 is provided with a bar 22, attached to its front atone side, which bar preferably extends from top to bottom of the car,and its extremities are beveled, as best illustrated at 23 in Fig. 1.The bar 22 may be made entirely of metal, or it may be made of woodprovided with a metal facing.

The bar 22 extends a sufficient distance from the face of the car tocontact with the bow portion of the spring 20 and compress the same whenthe car is passing a floor.

In operation when the car is out of contact with the spring 20 theweight of the latch 15 at its head is sufficient to cause it to drop bygravity into engagement with the door-keeper 12, and thereby-force therack-bar 18 outward to a contact with the upper front end of the spring.When, however, the bar 22 of the car, when the latter is ascending ordescending, contacts with the spring 20, as shown in dotted lines inFig. 2, it compresses the said spring, and thereby forces the rack-bar18 in the direction of the door,-which movement of the rack-bar, byreason of its engagement with the latch 15, elevates the latter, takingit out of engagement with the door-keeper, thus permitting the door tobe opened, and the latch will stand in this position (shown in dottedlines, Fig. 2) until the car is carried out of contact with the spring.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with a latch consisting of aheaded latch-bar eccentricallypivoted, and having teeth produced belowits pivotal point upon the under edge, of a' rack engaging with theteeth of the latch-bar, and a bowspring contacting with one end of saidrack, substantially as and for the purpose specified.

2. The combination, with a latch-bar eccentrically pivoted at one endand having teeth produced upon its under edge below the pivot, of arack-bar engaging with the teeth of the latch-bar, a bow-sprin g rigidlysecured at one extremity and bearing against the rack-bar at its otherend, and means, substantially as shown and described, for compressingthe said spring, as and for the purpose specified.

3. In a latch for the doors of elevator-shafts, the combination, with adoor provided with a keeper, having attached to its face an outwardly-extending bar, of a latch secured to the door-jamb of theelevator-shaft, consisting of a headedlatch-bar eccentrically pivoted atone end and provided with a series of teeth in the under face of itspivotal end, a

rack-bar held to slide upon the jamb and en-.

J OHN JOHNSTON.

' WVitnesses:

J. F. ACKER, J r., (J. SEDGWICK.

